Apple Opens 512GB Mac Studio at $22,299, With $15,500 Spent on Memory
Apple's 512GB M5 Ultra Mac Studio is back at $22,299, and $15,500 of that bill is unified memory alone. For local inference, the arithmetic is the story.
Vlad Makarovreviewed and published
Seven months after Apple pulled the 512GB option from its store amid a memory shortage, the configuration is back. Since 28 October, the M5 Ultra Mac Studio can be ordered with 512GB of unified memory, and Apple's US store lists the cheapest such build at $22,299.
What the Upgrade Actually Costs
MacRumors reports the sequence plainly: you first configure the M5 Ultra with a 36-core CPU and 80-core GPU, which starts at $6,799, and the 512GB memory option then adds $15,500. That works out to about $30 for every gigabyte of upgrade. Add 16TB of storage and the configurator reaches $29,799. The M5 Max Mac Studio still stops at 128GB.
A MacRumors forum commenter, Beau10, ran the comparison that Apple does not print: the 256GB step was previously priced as a $4,000 upgrade for 160GB, about $25 per gigabyte, which would imply roughly $10,400 for 512GB. The store charges $15,500. That is a commenter's arithmetic and not Apple's, but it is the fairest yardstick anyone has put on the page.
Why Capacity Sets the Ceiling
For local inference the interesting number is not the 80-core GPU. It is 1.2TB/s of memory bandwidth and a 512GB ceiling that decide which weights fit in one box, and Apple's August newsroom post sold exactly that framing, positioning the chip for on-device AI with an "up to 4.3x faster" claim the company has not broken down by workload. Bandwidth sets token speed, capacity sets model size, and both are soldered to the board. One commenter in the r/LocalLLaMA thread put the pricing more bluntly: "the first 256 gb plus the gpu is cheaper than the second 256 gb of ram, what?"
Two Machines, One Model
The timing is not accidental. On 15 October, MacRumors reported that Meta's Muse Spark Open, an 816-billion-parameter open-weight model, was demonstrated on two 512GB M5 Ultra Mac Studios running MLX. MacRumors describes the pair as behaving like one supercomputer with a terabyte of unified memory. At today's minimum price those two boxes cost $44,598 before any storage upgrades, which is the real entry ticket for the class of model Apple and Meta are now advertising.
What's Next
The option shipped on the late-October schedule Apple promised in August, so the supply question that hung over the M3 Ultra never materialized here. The pricing question did. A five-figure memory upgrade buys capacity at prices that sit close to datacenter hardware, and the same money rents a great deal of hosted inference. Whether the machine exists is settled; whether running the weights yourself is worth that is not.
